/**
 * Created by Administrator on 2019/6/17.
 */

var nav = document.querySelectorAll(".nav > li");
var main = document.querySelectorAll(".main > div");

for(var i = 0;i < nav.length;i++){
    nav[i].index = i;
    nav[i].addEventListener('mouseover',function () {
        for(var k= 0;k < nav.length;k++){
            nav[k].classList.remove('active');
            main[k].classList.remove('active');
        }
        this.classList.add('active');

        main[this.index].classList.add('active');
    });
}